Amalgam press



G. B. EBERENZ vAMALGAM PRESS Aug. 2 0, 1940..

Filed March I5, 1958 INVENTOR. BE/E/VZ Patented Aug. 2o, 1940 y UNITED STATES PATENT OFFICE N This invention relates to an improved amalgam press.

When an amalgam is prepared, usually there is an excess of mercury in liquid form that is not amalgamated with the solid metallic ingredient. For instance, when a dental amalgam of mercury and silver is prepared, excess liquid mercury is commonly present. Heretofor'e, it has been a diicult operation to remove' excess mercury and to produce a perfect amalgam. When an amalgam having excess free mercury is used for lling teeth, the quality and the life of thelling may be seriously impaired. Further, such an amalgam does not lend itself properly to the operation of lling teeth. Excess mercury may, in some instances, be forced from the amalgam by the plugging tool used to pack the filling into the cavity.

It has been common practice to attempt to squeeze excess mercury from dental amalgam, by hand, which is not emcient and may contaminate the amalgam.

It is a primary object of the present invention to provide a press that can be advantageously used to remove excess mercury from any type of amalgam that is prepared for any purpose.

A further object is to provide a press of this character that can be disassembled readily for iilling, cleaning and repairing, as well as removing the amalgam.

Other objects and advantages reside in details of design and construction, inclusive of means for eliminating handling of the amalgam, which will be more fully disclosed in the following description, and in the drawing wherein,

Figure 1 is a plan view of an amalgam press built according to a preferred form of the present invention;

Figure 2 is a longitudinal section of the same; and

Figure 3 is a transverse section taken on line 3-3 of Figure 2.

In the drawing, reference character 5 denotes a cylinder in which is operably positioned a piston or plunger 6 that terminates in a hand-piece 1.

One end of the cylinder is covered by means of a' screwed cap 8, which effects a sealed closure around the 'piston by means of a packing gland 9. 'Ihe cap 8 is concave as at 8a, forming a funnel for the cylinder to facilitate pouring amalgam into the press when the piston is withdrawn. The other, or discharge end of the cylinder is covered by another screwed cap or nut ID that holds a swivel'nozzle I2. Securely clamped across the discharge end of the cylindery is a filtering medium, such as a disk of chamois skin I3, that is preferably supported by a screen-like perforated plate I4, both of which are interposed' between the bore of the cylinder 5 and the hole in the nozzle I2. Since the form of the-invention killustrated is intended for hand use, a linger bracket I5 is provided on the cylinder for the convenience of the operator.`

In use, the piston or plunger 6 is withdrawn to empty the bore of the cylinder which is then to be lilled with the amalgam, by pouring it through cap 8.

After the amalgam has been placed in the cylinder, the plunger or piston 6 is forced inwardly, whereupon liquid mercury is pressed from the amalgam through the chamois I3, the screen-plate I4, and may be returned to a mercury container by means of the nozzle I2. The nozzle is flanged as at I2a so that in assembling the lter element onto the cylinder, the nut or cap IU will turn while the flange of the nozzle will hold the lter parts securely in place without turning them, which might distort the chamois. While the lter supporting element I4 has .been shown as a perforated plate, a wire screen of suitable strength or any other screen element may be used.

As hereinabove mentioned, the form of the improved amalgam press illustrated and described, is intended for hand use and primarily for service in a dentists oce or in a dental laboratory. However, it will be readily understood that presses built according to this invention may be constructed on a much larger scale for industrial purposes, and well-known mechanical means may be used to force the compressing piston into the cylinder instead of the hand-power plunger shown.

Preferably, all parts of the improved amalgam press should be made of material that will not amalgamate with mercury, such as strainless steel.

The ltering medium, which, in preferred form, is a disk of chamois skin, serves the dual purpose of a filter and a gasket to aid the leakproof closure of the nozzle end of the cylinder.'

When used in dental work, the press has the further advantages of permitting an operator to prepare an economical small amount of amalgam at one time and it eliminates all necessity for having the amalgam come in contact with human hands, which might contaminate it.

After all excess liquid mercury has been pressed from the amalgam, the cap ID, lter I3 and screen I4 may be removed, and the amalgam Aus in its iinished form may be ejected from the cylinder 5 by means of the piston 6, and the former method of hand handling or pressing is thus dispensed with. Even a slight contamination of dental amalgam, as from natural oil from the` hands, may impair the quality of the filling.

What I claim and desire to secure by Letters Patent is:

1. Azdevice of the character kdescribedcomprising an open endcylinder, a piston slidably tted therein, a disk lter element positioned against the open end of the cylinder across the opening therein, a similarly shaped filter-supe porting screen element positioned adjacent the lter element, a swivel discharge nozzle for the cylinder, and a threaded cap-nut on the cylinder for drawing the nozzle, the `1^11ter element and the lter screen toward the open end of said cylinder without rotation of said nozzle or lter element.

2. A device of the character described comprising an open end cylinder, a piston slidably tted therein, a disk filter element positioned against the open end of the cylinder racross the and the lter are clamped between the flange and the cylinder `without rotation of the flange or lter.

GEORGE B. EBERENZ. 

